Silent in order to pay attention (6)
I believe the answer is:
listen
'pay attention' is the definition.
(I've seen this before)
'silent in order' is the wordplay.
'in order' is an anagram indicator (the letters in a new order).
'silent' is an anagram of 'LISTEN'.
'to' acts as a link.
(Other definitions for listen that I've seen before include "Attend (to a sound)" , "Take notice" , "Follow advice" , "Make an effort to hear" , "Give ear (to)" .)